Gastro help please, 24F with severe nausea 3 months and worsening GI issues over the last few weeks

Hi, I don’t know if this is the right place to post but I am desperate. I am a 24 year old female. In mid October/early November I had COVID, food poisoning, and then a bad cold back to back. Then suddenly one day, 3 months ago, I started having nausea after eating. This escalated severely and my food intake was down a lot. I lost 15lbs in a month. I did 3 weeks on Omeprazole with no change. I was prescribed Reglan (didn’t help and made me feel awful too). Things were real bad in the end of December and I didn't eat for a complete week. I was so tired and weak with minimal energy and bedbound. I started force feeding myself and taking Zofran around the clock. It was still miserable though. The doctor started me on Amitryptaline off label and then switched me to Mirtazipine which I’ve been on since the beginning of January. In mid-January I felt a little bit better and consumed regular food without much nausea for about 2 weeks. Throughout this entire 3 month period, I had once-twice weekly explosive diarrhea episodes after eating. However, after those good 2 weeks, things took a turn for the worse. I started having multiple times daily diarrhea, bad stomach pain (upper left side) and lower abdominal cramping, and of course the severe nausea. I'm retching after eating a few bites of food it's awful. The last 5 days though, I haven’t been able to eat at all. I've had full blood panels, tested for celiacs, etc, had a gastric emptying scan, stool samples for bacteria and parasites. Everything is normal. I am awaiting calcprotectin results. My doctors are stumped and I’m getting worse and worse by the day I’m legit fearful for my life. Currently awaiting endoscopy and colonoscopy testing. Any advice or more things/tests to look into would be helpful. Currently getting care at Kaiser, should I just pay out of pocket to go somewhere else??? I’m desperate for help and it feels like nobody will help me. A doctor literally told me the other day they can’t do anything except have me take Zofran and Imodium because they don’t know what to do and don’t want to accidently make me worse.